1. Always use clichés. Fanfic readers prefer their fiction to be comfortable and familiar. Coming up with innovative plots twists and new interpretations of the characters only confuses them.
2. Don’t watch too many episode of the actual show. Base your fanfic on other fanfics, not the show. Remember, if you’ve actually seen the show, you might come up with a fresh twist, or realistic characterizations. This would not help you achieve that derivative feel a bad fanfic writer strives for.
3. Don’t forget your best friend - Mary Sue. What could be more entertaining than having a ridiculously idealized version of the author taking center stage and elbowing everyone else out of the way. Geez, you’d think readers actually want to read about their favorite characters instead of you. Don’t listen to the critics, it’s YOUR story, make it all about YOU.
4. Exposition! If you want to advance the plot, don’t bother wasting time with character development, interior dialogue, or actually writing those pesky action scenes. Just have someone show up out of the blue and explain everything in detail. Don’t bother to create an actual character or anything. All Ms. or Mr. Exposition needs to do is pop in, say their piece and get out.
5. Ah Romance! Everyone knows that if a show has one male and one female character they should get together and live happily ever after. Forget mundane realities such as compatibility and sexual chemistry. Ignore obstacles such as the chain of command. And, if you lack any experience of your own to guide you, just have the characters act like they’re in a Harlequin novel. So what if it’s Sci-Fi actioner featuring hard-ass military personnel trying to save the galaxy, nothing is more important than their love, damnit!
6. Plotting, who needs it. Structuring a story so that it has a beginning, middle and end is just so old fashioned. Don't worry about resolving the main conflict or wrapping up any loose ends. Start to write, keep going until you get bored, then quit.
7. Series! If one story is good, than 25 are better. You don’t have to go to the trouble of thinking up a new plot for each installment. Simply change the location and the minor character’s names and have them repeat the action over and over and over again. This saves both time and effort and doesn't strain the readers' imagination.
8. Songfic! What could be more plausible than to have a 45 year old character listen to the latest crappy song from some flavor of the month boyband and muse on how it really captures the essence of his romantic situation. Sure he’s your father’s age, but that’s no reason to assume he doesn’t have the same taste in music as a 14 year old girl. Remember, song lyrics are a fine substitute for dialogue, action and/or plot.
9. Crossover! Feel free to combine your two favorite shows. It doesn’t matter if they inhabit two mutually exclusive genres (i.e. Sci-Fi/Soap Opera), or that the shows take place during different historical eras. I can't think of any reason why 'Dawson's Creek' and 'Star Trek Voyager' wouldn't be a perfect mix. So go ahead, do that 'Buffy The Vampire Slayer' - 'Bugs Bunny' crossover, and don’t make it a parody!
10. Style is Everything. Be creative. Spell the character’s names differently every time, get your physical descriptions wrong (i.e. Buffy a brunette, Spike a redhead). Start the story in the present tense, then switch, without explanation, to an extended flashback. Typos, grammatical errors and run-on sentences are perfectly ok. Or, my personal favorite, never use anyone’s name during dialogue, so that it’s virtually impossible to figure out who said what. After all, you’re not getting paid for this! Readers shouldn’t expect clarity and consistency from you.
11. High School Rules! If you're writing about a show set in an extremely interesting universe, such as a space ship, or is about contemporary people in an extremely interesting setting, such as monster hunters (both human and supernatural), churn out endless stories about your heroes in a modern American high school. No, I don't mean flashbacks to the actual character's high school experience to learn more about them. That might be interesting and would require some research to eliminate anachronisms. (e.g. before the 21st century, cell phones, Facebook and Twitter didn't exist, and the internet was in its infancy.) Just plunk the entire cast into school with no explanation, and for the love of Mike, don't have them do anything interesting. Instead, have them go through a mundane day. It doesn't matter if the cast members are a variety of ages, or came from different parts of the country - just have them all in the same class for some reason.
11.a. This also applies to "Coffee Shop" fics.
12. Rule Britania! If you're from Great Britain, and you want to write about American characters, don't bother to get an American beta reader to go over the story to remove the britishisms. It doesn't take the reader out of the story at all when Sam and Dean Winchester "laugh like drains", or Bobby Singer says "whilst". This also applies to words such as "lift", "Boot and Bonnet" when referring to a car's trunk and hood, or calling a sweater a "jumper".